Pyrolysis of COVID-19 disposable masks and catalytic cracking of the volatiles.

The disposable masks generated in the battle against COVID-19 has attracted wide attention in the world. Pyrolysis can convert the masks into useful chemicals and fuels. In this work, the masks are pyrolyzed at temperatures of 400-580 °C and the volatiles generated are cracked without or with catalysts at 440-580 °C. The catalysts used include metal oxides (Al2O3, kaolin, Fe2O3, CeO2, TiO2) and molecular sieves (HZSM5, HY, ß(25H), ß(60H)). The yields and composition of gas and liquid products are studied in detail where the tetrahydrofuran (THF) soluble compounds are defined as the liquid product and the n-hexane soluble compounds are defined as the oil. The liquid product and the oil were identified by GC-MS and quantified by GC. Results indicate that 440 °C is sufficient for the masks' pyrolysis and the yields of gas, liquid product and oil are 23.4, 74.7 and 42.1 wt%, respectively. About 30% of the liquid product are C6-C35 hydrocarbons while about 70% are C36-C70 hydrocarbons trapped in the GC column (termed as column residue). The gas products are mainly C5, propylene and butene, accounting for 54.8%, 22.8% and 14.5% of the total gas product, respectively. Cracking of volatiles over various catalysts converts the liquid product mainly to propylene, butene and smaller organic gases. TiO2, HY and ß(60H) are good catalysts, especially ß(60H), which increases the yield of gas product to 86.5 wt% with 73.0% being ethylene, propylene and butene at 580 °C.

Clnk plays a role in TNF-alpha-induced cell death in murine fibrosarcoma cell line L929.

Clnk, as a third member of the Blnk/SLP-76 adapter family, is involved in the positive regulation of immunoreceptor signaling. Here we provide findings that Clnk may be is required for TNF induced cell death, it functions downstream of RIP3 and promotes TNF- induced ROS generation and MLKL tetramer formation and subsequent necrosis of L929 cells. Therefore, Clnk, as an adaptor protein, may take part in the other cellular processes.

Effects of high temperature after pollination on physicochemical properties of waxy maize flour during grain development.

BACKGROUND: Waxy maize is grown in South China, where high temperatures frequently prevail. The effect of high-temperature stress on grain development of waxy maize is not known. RESULTS: High temperature decreased the grain fresh weight and volume, and lowered the grain dry weight and water content after 22 days after pollination (DAP). Plants exposed to high temperature had low starch content, and high protein and soluble sugar contents at maturity. Starch iodine binding capacity and granule size were increased by heat stress at all grain-filling stages. The former parameter decreased, while the latter parameter increased gradually with grain development. High temperature increased the peak and breakdown viscosity before 30 DAP, but the value decreased at maturity. Pasting and gelatinization temperatures at different stages were increased by heat stress and gradually decreased with grain development under both high-temperature and control conditions. Gelatinization enthalpy increased initially but decreased after peaking at 22 DAP under both control and heat stress conditions. High temperature decreased gelatinization enthalpy after 10 DAP. Retrogradation percentage value increased with high temperature throughout grain development. CONCLUSION: High temperature after pollination changes the dynamics of grain filling of waxy maize, which may underlie the observed changes in its pasting and thermal properties.

Effects of high temperature during grain filling under control conditions on the physicochemical properties of waxy maize flour.

The effects of high temperature during different grain filling stages (1-15 d and 16-30 d after pollination) on the physicochemical properties of four varieties of waxy maize grain were studied. Heat stress during grain filling decreased grain weight and starch deposition, while it increased protein content, starch granule size, abnormal granule numbers and iodine binding capacity. These effects were more severe when heat stress was introduced at early development stage than at late grain filling stage. The peak intensities and crystallinities were decreased when plants were exposed to high temperature at early development stage. By contrast, responses to high temperature at late development stage were variety-dependent. High temperature during grain filling decreased the peak and breakdown viscosities and increased the gelatinization temperature and enthalpy, and retrogradation percentage of flours, especially during early development stage. In conclusion, high temperature during grain filling changed the grain proximate and starch structure, resulting in the deterioration of pasting and thermal properties.